title: Comparative study of pregnancy outcomes between day 3 embryo transfer and day 5 blastocyst transfer in patients with progesterone elevation.
abstract: OBJECTIVE
  To explore the effects of progesterone (P) elevation on pregnancy outcomes of day 3 embryo and day 5 blastocyst transfer.
  
  
  METHODS
  Clinical outcomes (pregnancy and ectopic pregnancy rates) following day 3 embryo and day 5 blastocyst transfer cycles were retrospectively analysed. Day 3 embryo and day 5 blastocyst transfer cycles were divided into normal P level (P ≤ 1.5 ng/ml) and P elevation group (P > 1.5 ng/ml), based on the serum P level on the day of human chorionic gonadotropin (hCG) administration.
  
  
  RESULTS
  A total of 2868 cycles were analysed. In day 3 embryo transfer cycles (n = 2345), the clinical pregnancy rate was significantly higher in the normal P level group compared with the P elevation group (55.4% versus 46.7%, respectively) and the ectopic pregnancy rate was significantly lower in the normal P level group compared with the P elevation group (2.8% versus 7.9%, respectively). In day 5 blastocyst transfer cycles (n = 523), there were no significant differences in the clinical pregnancy and ectopic pregnancy rates between the two groups, based on the P level.
  
  
  CONCLUSIONS
  These preliminary findings suggest that day 5 blastocyst transfer should be adopted for patients with P elevation on the day of hCG administration.
authors.affiliation: Reproductive Medical Centre, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China.
authors.forename: Rui-Rui
authors.initials: RR
authors.lastname: Li
authors.forename: Yue-Zhi
authors.initials: YZ
authors.lastname: Dong
authors.forename: Yi-Hong
authors.initials: YH
authors.lastname: Guo
authors.forename: Ying-Pu
authors.initials: YP
authors.lastname: Sun
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Su
authors.forename: Fan
authors.initials: F
authors.lastname: Chen
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D006063:Chorionic Gonadotropin / Q000627:therapeutic use*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000000981:diagnostic imaging / Q000628:therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011271:Pregnancy, Ectopic / Q000000981:diagnostic imaging / Q000503:physiopathology; D011374:Progesterone / Q000097:blood*; D012189:Retrospective Studies; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D006063:Chorionic Gonadotropin; D011374:Progesterone
keywords: Progesterone elevation; day 3 embryo transfer; day 5 blastocyst transfer; pregnancy outcome